High-throughput investigations of configurational-transformation- dominated serrations in CuZr/Cu nanolaminates

WY Wang and B Gan and DY Lin and J Wang and YG Wang and B Tang and HC Kou and SL Shang and Y Wang and XY Gao and HF Song and XD Hui and LJ Kecskes and ZH Xia and KA Dahmen and PK Liaw and JS Li and ZK Liu, JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY, 53, 192-199 (2020).

DOI: 10.1016/j.jmst.2020.04.024

Metallic amorphous/crystalline (A/C) nanolaminates exhibit excellent ductility while retaining their high strength. However, the underlying physical mechanisms and the resultant structural changes during plastic deformation still remain unclear. In the present work, the structure- property relationship of CuZr/Cu A/C nanolaminates is established through integrated high-throughput micro-compression tests and molecular dynamics simulations together with high-resolution transmission electron microcopy. The serrated flow of nanolaminates results from the formation of hexagonal-close-packed (HCP)-type stacking faults and twins inside the face-centered-cubic (FCC) Cu nano-grains, the body-centered-cubic (BCC)-type ordering at their grain boundaries, and the crystallization of the amorphous CuZr layers. The serration behavior of CuZr/Cu A/C nanolaminates is determined by several factors, including the formation of dense dislocation networks from the multiplication of initial dislocations that formed after yielding, weak-spots-related configurational-transitions and shear-transition-zone activities, and deformation-induced devitrification. The present work provides an insight into the heterogeneous deformation mechanism of A/C nanolaminates at the atomic scale, and mechanistic base for the microstructural design of self-toughening metallic-glass (MG)-based composites and A/C nanolaminates. (C) 2020 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

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